Development of Air Multiplier for Application in the Automotive Industry

Engine cooling fans are an essential component of the engine cooling system which is used to dissipate the excess heat generated by the combustion of fuels inside the engine. This project consists of designing the fan and analyzing it for its strength in structure using the Finite Element Method (FEM) approach and the flow of air around it using Computational Fluid Dynamics (CFD) approach. An important factor for successful fan design is to fully understand the complex flow field within the fan. This understanding enables optimization. Computational Fluid Dynamics (CFD) techniques can be beneficial to provide insight to the fan design process. Not only can velocity vectors and pressure contours be computed, CFD can also provide critical information such as efficiency, flow uniformity at the exit, circulation or separation zones, locations of potential cavitations and noise generation. The design of the fan was conducted in phases, starting with calculating all the required dimensions followed by analytical models to prove the concept. Accordingly, finite element analysis and computational fluid dynamics were performed on simulation models. The overall shape of the first iteration was conceptualized with the aid of the above guidelines. The results obtained from the analytical studies indicated a potential for a successful design that met most of the above outlined parameters.

2000

With sponsorship from the U.S. Department of Energy, a research project has designed, fabricated and tested improvements to an air conditioner outdoor unit fan system. The primary objective was to improve condenser fan performance while reducing motor power. We also examined potential changes to the condenser exhaust configuration to enhance air moving efficiency performance. A secondary objective was to provide sound reductions as lower noise AC equipment is important to consumers. Within conducted tests, an improved high efficiency fan design and advanced exhaust diffuser section reduced fan motor power requirements by approximately 49 W (26%) while providing superior air flow. When mated with a brushless DC motor, the same configuration can reduce fan power use by nearly 100 Watts (50%). The overall increase to total system efficiency (EER and COP) is approximately 2-4% depending on configuration. The reduced fan unit power could be very desirable for utilities concerned with peak demand, since the change provides reliable load reductions on peak. The changes in exhaust configuration are also important in that they allow for slower fan speeds to obtain equivalent flow. When coupled with a developed vortex shedding control strip and an asymmetrical fan design we showed reductions to fan sound levels of 1-2 dB according to ARI Standard 270-1995.

International Journal of Environmental Science and Technology, 2012

This study presents energy efficiency measures in fans as an important energy consumption facility in the industry and common usages by identifying the sources of energy loss and applying methods to reduce those losses, which are one of the critical issues in protecting the environment and in global warming. The carbon footprint can be lowered by reducing the energy consumption of a fan over its life cycle. The main sources of energy loss in fans such as noise, vibration, lubrication, temperature of the bearings, installation type, damper and filter, especially pulley and belt system compared to electrical variable speed drive, are theoretically and experimentally discussed. The laboratory results show that the mechanical variable speed drive is one of the critical sources of energy loss in centrifugal fans. The results also show that by changing the drive with an electrical variable speed drive, the energy usage can be substantially optimized. For instance, using an electrical variable speed drive has reduced the energy loss up to 38.5 % with regard to the speed and according to the different flow rates. Moreover, based on the results derived from the equations and figures, it can be concluded that a considerable amount of energy per year, as well as the related cost can be saved and this shall be noted particularly in industrial applications.

2017

Ceiling fans play a pivotal role in indoor cooling and thermal comfort. In this paper a computational framework, validated by experimental data, is presented for the design enhancement of ceiling fan blades with the objective of enhancing energy efficiency. A parametric study is performed by steady-state numerical simulation of three-dimensional airflow. Specifically, the parameters considered in the study are rake angle, bend angle and bend position. Rated air delivery, power consumption and service value at different rotational speeds are set as performance measure. The recommended geometry from the parametric study is tested and compared with the original geometry. The results indicate that airflow and service value increase by 21% and 54% respectively at 300 revolutions per minute and power consumption is reduced by 22%.

Recent studies on automotive engine cooling fan systems carried out in partnership between LEMFI and Valeo have led to the definition of a range of efficient stator designs. It was shown that an adequate rotor-stator coupling could yield significant efficiency gains over the whole range of Valeo fans with diameters ranging from 280 mm to 460 mm. Efficiency gains ranging from 12 percentage points for the 350 mm fan diameter to 2 points for the 460 mm were estimated by using a simplified radial equilibrium design (SRE). The first two rotor-stator prototypes with 320 mm and 380 mm diameters, respectively, confirmed these numerical results. Maximum efficiency gains of 10 and 4 points were achieved for these prototypes at the nominal flow rate on normalized aerodynamic test benches. Recent developments and designs for various fan system diameters are reported here, which further confirm the initial SRE findings. The present study then describes a newly developed aeroacoustic test facility dedicated to automotive fan systems. The influence of the rotor-stator coupling is then shown by comparing the rotor alone and rotor-stator configurations, not only on the overall performances and velocity fields at the system outlet measured by a 5-hole probe, but also on the noise generated by the fan systems for various flow conditions. At the nominal flow rate, the efficient stator are shown to bring little or no extra noise if the number of stators and the rotor-distance are carefully chosen. At other flow rates, additional noise might be expected. Fan Noise 2003 2

A numerical study is carried out to investigate the effect of the addition of winglet to the end of blade on the axial fan performance. Validation and assessment of the used computer program FLUENT 6.2, is carried out by comparing its result with previous researcher. Simulation is then carried out to analyze the flow pattern with and without a winglet attached to the fan blade. Velocity distribution produced numerically showed that the winglet suppresses the secondary flow at the tip gap. Pressure distributions also confirmed the winglet advantages. Calculated performance of the fan used showed general increase of the fan efficiency with 3.5% above those without winglet at the optimum efficiency point and with up to 6 % at off design point.. 1. INTRODUCTION Fans demand minimum gaps in order to facilitate operation, this gap tip clearance flow is known to have detrimental effects on the axial fans performance. The static pressure difference between the suction and the pressure side o...

2009

In a warm environment air movement with elevated velocity is a well-known cooling strategy. The air movement can be generated by cooling fans (e.g. ceiling fan, table fans, etc.). Appearance, power input and price are the main parameters considered today when purchasing cooling fans, while their cooling capacity and efficiency of energy use are unknown. Cooling fan efficiency index defined as the ratio between the cooling effect (measured with a thermal manikin) generated by the device and its power consumption is a measure of the efficiency of the fans. The index was determined for a desk fan and two identical computer fans working simultaneously. The results showed that the computer fans generated the same cooling effect (around -2°C) with less than half power consumption (7 W instead of 16-20 W). It means that the computer fan's efficiency is double than the efficiency of the desk fan. The computer fans caused a more homogeneous cooling effect than the desk fan.

Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoustic performance of the fan were considered via solving the conservation of mass and momentum equations in their unsteady form. To validate the acoustic code, NACA 0012 airfoil was simulated in a two dimension domain and the emitted noise was calculated for Re=2×10 5. Good agreement between numerical and experimental results was observed by applying FW-H equations for predicting noise of the fan. To validate the simulated aerodynamic results, a Bladeless fan with a 60cm diameter was constructed and experimentally tested. In addition, the difference between the experimental and numerical results was acceptable for this fan. Moreover, the experimental results in the present study showed that this fan is capable to be designed and used for various industrial applications.

Virtual design of automotive engine cooling fan systems is presented in ideal/test-bench and installed/under the hood configurations. Several comparisons with measurements are provided to assess the accuracy of the numerical models with increasing size and complexity.

2001

Applied Sciences, 2017

To meet humans' need of enhancing the quality of life, the high-performance stand fan has become an essential appliance in every family. On the other hand, energy saving can not only solve the problem of environment protection, but also can reduce the cost of energy consumption. However, the aerodynamic performance and flow characteristics of the stand fan are rarely investigated and analyzed in a systematical manner. Therefore, this research intends to investigate the physical mechanism of the flow pattern and identify the design parameters of the stand fan by combining numerical and experimental methods. First of all, both the structure and performance of a commercial 14-inch stand fan are chosen for analysis and are set as the reference for the fan. The stand fan can be divided into the impeller and the protective cover. Clearly, the impeller blades have a great influence on the fan performance, so they are the first design target. In this work, CFD (computational fluid dynamics) software Fluent (version 14.5, ANSYS Inc., Canonsburg, PA, USA, 2012) is used to analyze and observe the corresponding influences on flow fields and aerodynamic performance by changing the design parameters such as the setting, twist, and inclination angles. Then, the protective cover is studied, improved and integrated with the designed impeller to further enhance the performance of the fan. The protective cover is modified by varying the spacing between the blade tip and cover, as well as varying the shape and angle of ribs to improve the fan's flow field and performance. Finally, the optimal fan mockup is made via CNC (computer numerical control) technology. Also, its acoustics and performance have been measured to validate the accuracy and reliability of the numerical simulation. The testing results show that the optimally designed stand fan is better than the reference fan with a significant 54% increase in max flow rate. In addition, it has more uniform velocity distribution compared with the reference fan to achieve a comfortable feeling for the human body. In summary, this research successfully establishes a reliable and systematic scheme to design the stand fan. Also, the corresponding performance influences caused by those important parameters are analyzed and summarized to serve as the design reference for the stand fan.

Energies

The article discusses the process of designing and testing as well as their results, carried out in order to increase the efficiency of axial fans, implemented as part of the European project INESI. Modifications of existing solutions based on rapid prototyping methods were presented. Scanning, FEM and CFD numerical calculations and 3D printing were used for that purpose. Rapid prototyping involved the use of a steel blade base and 3D-printed complex aerodynamic shapes that were bonded to create completely new blades. After their installation on the new rotor, enabling the angle of attack adjusting, a number of verifying tests of the fan were carried out. The solution was successfully tested and the results are discussed in the article.

The prime objective of this work is to determine the relationship between the mechanical and aerodynamic characteristics of the fan when the blade position is default and when it is changed and to find out which position gives optimum output at given power and given working conditions and according to the change of environment. In this experiment, the aerodynamic characteristic of an axial flow fan is going to be determined by measuring the static and total pressures in the suction and discharge sides of the fan for various flow rates. In this experiment, for different blade angle, flow velocity is measured and relationship between the change of blade angles and the flow velocity are plotted

Toshiba devised the bladeless fan (or Air Multiplier) concept in 1981. Researchers like James Dyson and Jafari et al. further developed it. Bladeless fans are more energy-efficient, safer due to the hidden blades, easier to clean, and more adjustable than conventional fans. From a performance point of view, bladeless fans are better because they multiply mass flow rate, eliminate buffeting, consume less power, and are quieter. This paper investigates the influence of the airfoil’s outlet slit thickness on the discharge ratio by varying the outlet slit thickness of an Eppler 473 airfoil from 1.2 mm to 2 mm in intervals of 0.2 mm. Results indicated that smaller slits showed higher discharge ratios. The airfoil with a 1.2 mm slit thickness showed a discharge ratio of 18.78, a 24% increase from the discharge ratio of the 2 mm slit. The effect of outlet angle on the pressure drop across the airfoil was also studied. Outlet angles were varied from 16∘ to 26∘ by an interval of 2∘. The airf...

International Journal of Automotive Technology, 2011

 Manufacturers of commercial vehicles are facing a substantial increase of heat release into the cooling system. The main sources for this increase are more stringent emissions leading to new combustion technologies and the increased power of engines. The total increase in the cooling requirement may be up to 20% over the current level. At the same time, the noise levels have to decrease and fuel economy has to improve. This forces manufacturers to think about new concepts and optimized efficiency of the cooling system. A bus engine cooling fan system is seen as one of the main means of vehicular fuel efficiency reduction. This is becoming a major factor in city noise, and the necessity of electromagnetic technical development is very great. This study features a highly effective BLDC motor for engine cooling fans, high effectiveness, and low noise most suitable fan Blade technical development, cooling Fan performance evaluation technical development.